Spinning apparatus is known having a spindle which is rotated at high speed and which carries a flyer. Mounted within the flyer and rotatable relative thereto is a yarn-package holder in which a yarn package is carried. The yarn is drawn off the package, passes axially back through the spindle and radially out through the flyer, then forms a balloon around the yarn package holder. The yarn is then drawn axially away from the device, thereby being twisted to a degree dependent upon the pulloff speed and the rotation speed of the spindle.
Such devices have proven themselves highly useful with relatively durable filaments such as cotton or synthetic-resin yarn. However in the twisting of more fragile filaments, such as fiberglass yarns, these devices are almost totally unusable. This is due to the very low tensile strength of such yarns in their unspun condition. For this reason it has heretofore been found necessary to use traveler-ring spinning frames for glass fiber yarns.